Line protractor



c. MEMLUCK 2,586,074

LINE PROTRACTOR Feb. 19, 1952 Filed Dec. 10, 1949 INVENTOR: Charles Memluck,

ATTORNEY.

Patented Feb. 19, 1952 v UNITED STATES PATENT OFFICE 1 j 2,586,074 LINEPROTRACTOR 7 Charles Memluck, Utica, Mich. Application December 10,1949, Serial No. 132,360

2 Claims.

The object of my improvement is to provide a device for use of buildersand contractors who may be in need of an instrument simple inconstruction and yet fully practical in determining horizontal outlinesof proposed excavations,

buildings, etc.

Another and more specific object of my improvement is to provide such aprotractor which will be adapted to be used in pairs, each of theprotractors being used in combination with other elements whereby linesat angles of 90 degrees to the baseline passing through the axis of bothprotractors will be automatically indicated on the respectiveprotractors.

I shall now describe my improvement with ref erence to the accompanyindrawings, in which:

Fig. 1 is a perspective view of my protractor set up for use;

Fig. 2 is a top plan view of the protractor shown in Fig. 1;

Fig. 3 is an exploded view of the component parts of my protractor, theparts being shown in perspective;

Fig. 4 is a sectional view on line 4-4 of Fig. 2.

Similar numerals refer to similar parts throughout the several views.

The protractor is to be used in conjunction with a vertical stake lwhich is to be driven into the ground H and fits telescopically oversaid stake. For that purpose the protractor includes a sleeve 12,including at its lower end a flange 13. A set screw l4 disposed radiallywith respect to the stake serves as a means of retaining the sleeve onthe stake at a desired height from the surface of the ground ll.

Supported by the flange i3 is the protractor proper made in the shape ofa disk l6 which is provided with a centrally located circular apertureIE to fit over the outer surface of said sleeve l2. The upper surface ofthe disk is divided by two diametrically-disposed lines crossing eachother at right angle and dividing said surface into quadrants, while themarginal portion of said surface in each quadrant is calibrated indegrees, as indicated by numeral IS, the calibrations beginning fromzero at the ends of one diametrical line and rising to 90 degrees inboth directions, that is clockwise and anti-clockwise, as best shown inFig. 2. While this calibration is preferred, it is not consideredcritical, permitting any other arrangement to be used if desired. At apoint I! at the end of one diametrical line the disk is perforated,permitting attachment of a cord 18.

Seated upon the disk is an angle indicator, generally identified bynumeral IS. The indicator includes a hub portion 20 provided with acircular aperture 2! to fit over said sleeve i2, a pointer 22, and -ashank 23. The latter has a longitudinal slot 24, permitting thecalibrations Ilia to be viewed from above. A V-shaped wedge 25 withinthe slot with a sharp end pointing at the calibrations helps in quicklyidentifying the same. An eye 26 at the outer end of the shank serves asa means for. attachment of another cord 21. Itwill be noted that theshank portion of the indicator i9 is raised above the surface of thedisk 15 but is disposed parallel thereto. Finally, to complete theassembly of the elements comprising my protractor, a collar 28 is placedabove the hub 20 of the indicator and secured in place by a set screw29. The collar is in contact with said hub 20 but is set in such amanner as not to interfere with the rotation of either the indicator H!or the disk IS.

The operation of my device is quite obvious. Once the baseline has beendetermined, as, for example, in laying the foundation of a building, astake is driven into the ground on said baseline at the intersectionwith an intended crossline. Another stake is driven on the same baselineat the intersection with another cross-line. Two protractors, asdescribed by me, are seated on the above-named stakes, and the disksthereof are connected by cord l8. This will automatically align onediametrical line 30 on each disk with said baseline and will set theother diametrical line on each disk at degrees to said baseline. If thecross-lines are to be set at 90 degrees to the baseline, all that isneeded to be done is to align the respective indicator with saiddiametrical line 30, as shown in Figs. 1 and 2. If any other angles aredesired the calibrations on the respective disk will quickly indicatethe setting. Cord 21 attached to the respective indicator may beextended from each protractor to a desired length, drawn taut, andfastened where desired. The respective angle of the indicator will beshown by calibrations as read with respect to the tip of pointer 22 orthe wedge 25 in shank 23.

It will be obvious that some changes may be made in the structure of myprotractor without deviating from the basic principle disclosed herein.

What I, therefore, wish to claim is as follows:

1. A device of the kind described, said device comprising, incombination, a vertical stake, a tubular sleeve thereon, the sleevebeing provided with a flange at its lower end, screw means within theflange to secure the sleeve against rotaa cord, the marginal portion ofthe disk being calibrated in degrees, and an indicator mounted above the,protractor for rotation about said sleeve, the indicator including ahub surrounding said sleeve, a pointer extending radially from the hubin one direction and a shank extending from the hub in the oppositedirection, the shank being provided with means for attachment to a cord.

said indicator including a portion extending from the hub towards saidcalibrations and a shank with a vertical slot, and a wedge-shaped memberwithin the slot, the point of the Wedge being directed towards arespective calibration.

CHARLES MEMLUCK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

